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How can I reduce JavaScript execution time to improve page load speed?
Asked on Feb 19, 2026
Answer
Reducing JavaScript execution time is crucial for improving page load speed and enhancing user experience. This can be achieved by optimizing scripts, deferring non-critical JavaScript, and minimizing the amount of JavaScript loaded initially.
Example Concept: One effective method to reduce JavaScript execution time is to use code splitting and lazy loading. Code splitting involves breaking down your JavaScript into smaller chunks that are loaded only when needed. Lazy loading defers the loading of non-essential scripts until they are required, reducing the initial load time and improving performance metrics like First Input Delay (FID).
Additional Comment:
- Use asynchronous loading for scripts that are not critical to the initial page render by adding the "async" attribute to script tags.
- Consider using a modern JavaScript framework or bundler like Webpack to facilitate code splitting.
- Audit and remove any unused JavaScript to reduce the overall size of the scripts being executed.
- Optimize JavaScript performance by using efficient coding practices and avoiding heavy computations on the main thread.
- Regularly test your site with tools like Google Lighthouse to identify JavaScript-related performance bottlenecks.
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